It's been a long time since I've used windows, but I think something like this would work.

Right click drive folders you want to deny access to, go to properties, open the security tab, press edit, then remove the users you don't want to have access to the drive.

Edit: Not sure if removing users completely or setting the deny flag on non admin users is the better option. But I think either should work for your scenario.
Just poke around and see what works best for you.